20 T. L. Lyon anv J. K. WILson 
In one flask the usual nutrient solution was not employed, as it was desired 
to ascertain whether a leguminous plant grown in a solution containing 
no nitrogen would liberate nitrogenous matter in the solution in appre- 
ciable quantities. The flask used for this purpose was pea flask no. 1302, in 
which the nutrient solution was composed of 1.5 grams KH2POu, 1 gram 
CaCl, 0.07 gram NazSO., and 0.5 gram Fe,(POx)2 + 8H2O; the flask was 
then filled with sterile tap water, the Fe:(PO:)2 + 8H2O remaining largely 
undissolved. 
After the contents of the flasks were sterilized and the young plants 
transferred, the cultures were taken to the greenhouse, where they remained 
for various periods. It was not intended to make any systematic study 
of the relation of the stage of growth to the quantity of organic nitrogen 
in the solution at harvest. This would have been impossible under the 
circumstances, for the plants were set out at different times and, since 
conditions affecting plant growth vary greatly in the greenhouse at different 
seasons of the year, no comparison of this kind could be attempted. The 
same difficulty would obtain in case a comparison of different plants 
was desired, except in the case of such plants as were placed in the green- 
house at about the same time. | 
When it was decided to harvest a plant, the flask was brought to the 
laboratory, and, after a photograph had been taken, the plant was removed 
from the nutrient solution and the dry matter and nitrogen were determined 
in the entire plant including the roots. A plating of the nutrient solution 
was made to determine whether the solution was sterile. The presence 
of any molds or bacteria thus detected excluded from the experiment 
the flask so contaminated. 
-The volume of liquid remaining in the flask was measured, and determina- 
tions were made of the nitrate nitrogen remaining in the solution, the 
ammonia nitrogen, if any, and the organic nitrogen present in soluble 
form. The deposit at the bottom of the flask was collected and a determi- 
nation was made of the organic nitrogen contained in it. The reason for 
ascertaining the quantity of nitrate nitrogen remaining in the solution 
was merely to observe whether the presence or absence of this form of 
_ nitrogen affected the liberation of organic nitrogen by the plant. 
A small quantity of nitrogen was contained in the germinated seed and 
plantlet placed in the flask, but there was no way by which this nitrogen 
